Optical receiver apparatus for quickly detecting loss of a composite optical signal input employing a loss-of-clock detector

摘要

An optical signal receiver apparatus contains: a photoelectric conversion circuit for receiving an optical signal conveying cyclic timing information, and converting the optical signal into an electrical signal conveying the cyclic timing information; a receiving clock signal extraction circuit for extracting a receiving clock signal indicating the cyclic timing information, from the electrical signal; and a loss-of- clock digital-detection circuit for detecting absence of a change in a digital level of the receiving clock signal.